Compound of gelatin and tannin and process of producing same.



UNITED STATES PATENT OFFICE.

JULIUS AL'ISCHUL, OF BERLIN, GERMANY, ASSIGI IOR TO THE AOTIEN-GESELLSOHAFT FUR ANILIN FABRIKATION, OF SAME PLACE.

COMPOUND F GELATIN AND TANNIN AND PROCESS OF PRODUCING SAME.

SPECIFICATION forming part of Letters Patent No. 658,747, dated October2, 1900.

Application filed November 11, 1898. Serial No. 696,l6l. (Specimensd T0(ZZZ whmn it may concern.-

Be it known that I, JULIUS ALTSCHUL, of Berlin, in the Kingdom ofPrussia, German Empire, have invented new and useful Improvements in theProduction of a New Com-- pound of Gelatin and Tannin; and I do herebydeclare that the following is a full, clear, and exact descriptionthereof, which will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to the production of a new compound of gelatinand tannin suitable for use as an intestinal astringent. Hithertogelatin tannin compounds which could be used in medicine as tanninsubstitutes have not yet been described, and several difficulties had tobe overcome in order to obtain a product adapted for such medicinal use.Thus it is well known that the precipitate obtained from aqueoussolutions of gelatin and tannin is subject to putrefaction. I have nowdiscovered that this property is essentially caused by the waterretained by the precipitate. I further have found that if this water isentirely removed a stable and non-putrescible product is obtained.Another diflticulty, however, arises from the behavior of the gelatintannin precipitate when exposed to heat. When this precipitate, afterremoving the mother-lyes by pressing off,is heatedfor instance, on thewater-bath-it melts at relatively-low temperature, forming a darkcoloredviscous and leather-like mass. By heating the same for a long time onthe waterbath it is possible to remove the water; but the productobtained in this way is strongly colored and does not possess theproperties of pure gelatin tannate. Thus it assumes a disagreeable tasteand smell when heated above 100 centigrade-for instance, in order tosterilize it-whereas pure gelatin taunate can be heated to 100 to 130centigrade without any decomposition. I have now succeeded in totallyavoiding the partial decomposition caused by the melting of the rawgelatin tannin precipitate by allowing the latter to dry at ordinarytemperature for a sufficiently long time previous to further drying itin the heat. I have found that when most of the water retained in theprecipitate has thus been removed by evaporation at ordinary temperaturethe remaining product can afterward becompletely dried at 100 centigradewithout meliing or decomposing. In this manner I obtain an almostcolorless substance free of taste and smell and being not decomposedwhen heated to temperatures of 100 to 130 centigrade. The pure and drygelatin taunate thus prepared contains about forty-five per cent. oftannin. By this high percentage of tannin my new product isdistinguished from the glue-tannate described by Bottinger, (LiebigsAnnalen, 244, 228,) which only contains thirty-four per cent. of tannin.

I have now found that the new product which I obtain from gelatin andtannin in the manner above described possesses the valuable property ofbeing nearly insoluble in the juices of the stomach, while it dissolvesreadily in the juices of the intestines. It can therefore be appliedwith great advantage as an intestinal astringent, which has no effect inthe stomach, but will only act in the bowels.

The following example may illustrate the production of the new product:The precipitate obtained by adding two hundred litres of afive-per-cent. solution of tannic acid to one thousand litres of aone-per-cent. solution of gelatin while constantly stirring is filteredoif, washed repeatedly with water until the excess of tan nic acid isremoved, and pressed: The cake obtained is coarsely ground, spread outin thin layers, and allowed to dry at 20 to 25 centigrade and atordinary or at reduced pressure until a sample does not melt any morewhen heated on the water-bath. The mass is then ground to a powder andcompletely dried at 100 centigrade. If desirable, the product canfinally be sterilized by heating it for several hours at about 105 to110 centigrade.

Having thus described my invention and in what manner it can beperformed, I declare that what I claim is 1. The compound of gelatin andtannin he rein described containinga nearly-constant proportion offorty-five per cent. of tannin and fit for use as an intestinalastringent, being nearly insoluble in the gastric juice, but readilysoluble in the juices of the intestine, forming an almost colorlesspowder, free of taste and smell, not put 'c'scible, very sparinglysolublein water and diluted acids, more readnary temperature, until asample does not ily soluble in alkaline liquids, being not demelt whenheated on the Water-bath, and composed by heating at temperatures fromfinallycompletelydryingtheproduetatabout '5 100 to 130 centigrade.substantially as de- 100 centigrade, substantially as described. 5scribed. I In witness whereof I have hereunto signed 2. Thewithin-described process of obtainmy name, this 26th day of October,1898, in ing a compound of gelatin and tannin for use the presence oftwo subscribing witnesses.

sisting in mixing diluted aqueous solutions 10 of pure commercialgelatin and tannin (gallotannic acid), pressing oi the precipitateproduced, allowing the same to dry at ordi- Witnesses:

C. H. DAY, HENRY HASPER.

i as an intestinal astringent, said process coni JULIUS ALTSOHUL

